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HTML

              
                <p>说明:鼠标在以下元素不断移动,将会不断执行一个数值累加事件,但中间分别加入了防抖和节流函数。</p>

<h2>防抖</h2>
<p>在鼠标停止移动后300ms执行一次数值累加事件。</p>
<div id="content">0</div>
<h2>节流</h2>
<p>在鼠标移动过程中,每300ms执行一次数值累加事件。</p>
<div id="content2">0</div>
              
            
!

CSS

              
                div{height:150px;line-height:150px;text-align:center; color: #fff;background-color:#ccc;font-size:80px;}
h2{margin: 10px 0;}
p{color:#666;margin:0;}
              
            
!

JS

              
                // 防抖函数
function debounce(func, wait) {
  let timeout = null;
  return function () {
    let context = this;
    let args = arguments;
    if (timeout) clearTimeout(timeout);
    timeout = setTimeout(() => {
      func.apply(context, args)
    }, wait);
  }
}

// test debounce
let num = 1;
let content = document.getElementById('content');
function count() {
  content.innerHTML = num++;
};
content.onmousemove = debounce(count, 300);



// 节流函数
function throttle(func, wait) {
  let timeout = null;
  return function () {
    let context = this;
    let args = arguments;
    if (!timeout) {
      timeout = setTimeout(() => {
        timeout = null;
        func.apply(context, args)
      }, wait)
    }
  }
}

// test throttle
let num2 = 1;
let content2 = document.getElementById('content2');
function count2() {
  content2.innerHTML = num2++;
};
content2.onmousemove = throttle(count2, 300);
              
            
!
999px

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